1. Field of the Invention
The present invention relates generally to insect control systems for structures, and more particularly, but not by way of limitation, to an improved method for injecting pesticide beneath or inside a structure in a uniform manner.
2. Brief Description of the Related Art
Numerous systems have been proposed for protecting buildings and homes from damage caused by pests, such as subterranean termites, which can do considerable structural and cosmetic damage over time. A common practice for treating infestation of pests into a structure is to pre-treat the ground under the structure with pesticide chemicals during the construction process. This is done by applying a substantial quantity of pesticides, such as termiticide, on the ground under the proposed structure before the slab is poured in an attempt to create a chemical barrier that will keep the insects from entering the structure.
The problem with this method of treatment is the amount of pesticide required to be used can be harmful to occupants of the structure as well as harmful to the groundwater. Furthermore, even though a large amount of pesticide is applied to the ground, the resulting chemical barrier nevertheless becomes ineffective over time as the chemicals break down.
With these problems in mind, other methods have been developed for the periodic injection of pesticide beneath structures. One particular method involves the drilling of holes in and around the slab for the injection of pesticide. This method has many drawbacks which include affecting the integrity of the slab, the mess of drilling through the slab, convenience of having to clear a path around the structure to permit access for the drilling, the need for the holes to be plugged, and the residual odor of the pesticide that escapes during the injection process. In addition, this process must be periodically repeated during the lifetime of the structure.
Considerable efforts have been made to alleviate the problems of post construction periodic injection of pesticides beneath the structure by placing an injection system beneath the structure during the construction process. Many of these systems involve placing a network of porous tubing beneath the structure. The problem encountered in these systems however is that the holes provided in the tubing have a fixed diameter and thus are susceptible to clogging. Because there is a preference to placing the network of tubing within the fill material positioned under the slab, the fill material often obstructs or clogs the holes. The holes can also get clogged by dead insects and other pests that may enter the holes in the tubing over the course of the lifetime of the system. When the holes become clogged or obstructed, they fail to deliver pesticide to the surrounding location, thereby creating a gap in the chemical barrier which can be exploited by pests.
Other injection network systems with fixed holes have attempted to prevent hole obstruction elaborate systems or by varying construction procedures. For example, systems have been developed where the holes are sheltered with wick-like membranes, soil screens, shower-type sprinkler heads, and sponges. Other systems attempt to keep the holes from being obstructed by surrounding the holes with specialized fill materials applied during the construction process. Each of these types of systems is complex and increases installation costs.
Another problem that has been encountered with pesticide injection systems of the existing art is that each of these systems tend to inject pesticide at decreasing rates along the length of the tubing. This is due to the fixed holes of the tubing allowing pesticide to be injected at a greater rate near the injection end of the tubing while the injection rate decreases as the distance from the injection end increases. Consequently, pesticide is applied in a non-uniform fashion. If a pesticide is not capable of being applied in a uniform and predictable fashion, the application of such pesticide generally will not comply with the requirements of the pesticide label, as required by federal law. As such, a system that is not capable of applying pesticide in accordance with label requirements is rendered inoperable.
To this end, a need exists for a pesticide injection system which is simple in design, inexpensive to install, easy to operate and maintain, and which distributes pesticide uniformly throughout the system. It is to such a system that the present invention is directed.